172 Cat Problem - DIY Decat?

[~nomad~]

Pretty sure the cat has perished on my 172. Lumpy as hell, slight backfire, engine light flashing and rotten egg smell.

If I am right and it is that, it seems like the time to decat the car. My question is, can I simply cut the cat part out and replace it with a section of pipe, welded in? I have done it on other cars, but not sure on the layout of the Clio, is there a lamba that would need relocating?

 

[.Kev.]

There are two Lambda sensors on a Ph2 172 before and after, you could cut the cat out and weld a bit of pipe in but its a funny old shape and if not done correctly may fowl the sub frame and cause a right racket, you often see them in the for sale section, or new from KTech for £100 or so. Worth doing though, i noticed a marked improvement.

 

[~nomad~]

stuck my head under and looks like the actual cat part could be cut out and replaced easy enough, and the lamba bosses could be left in place. Would have to get under it properly to confirm though.

Anyone know the diameter of the pipes on cat?

 

[TheEvilGiraffe]

What happens at MOT time dude ?

Plenty of cats up for sale on here from time to time usually £40-£50...

 

[~nomad~]

At MOT time i have a friendly tester

 

[TheEvilGiraffe]

Excellent news.

Get a proper de-cat bought, again lots on here from time to time, or have one made up if you know someone who can weld.

 

[~nomad~]

I know a superb welder, hopefully get it sorted tomorrow

 

[~nomad~]

For anyone interested I did this on sat, turned out a dodgy plug was causing the running prob, but we had the cat off so decided to decat anyway lol.

Car is defo more responsive on the throttle, not faster as such but feels good.

Noisewide, I wouldn't say its louder, but has a different more "raspy" sound. This is on a 172 Cup with a ktec steath and straight thru centre, so the only silencing is on the back box now.